SPECIES

Ivory-billed Woodpecker Campephilus principalis Scientific name definitions

Jerome A. Jackson
Version: 1.0 — Published March 4, 2020
Text last updated January 1, 2002

Systematics

Systematics History

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Originally described by Carolus Linnaeus (Linnaeus 1758a) based on "The Largest White-billed Woodpecker . . . Picus maximus rostro albo " of Catesby (Catesby 1731). The genus Campephilus was erected by Gray (Gray 1840), with " Picus principalis Linnaeus" designated as the type for the genus.

Geographic Variation

I have examined 204 specimens of adult Ivory-billed Woodpeckers that have locality data (though sometimes simply "Florida" or "Georgia"). Of these, 155 are from Florida. There are far too few specimens to say much about geographic variation in the species -except that the species seems to follow the classical pattern of larger birds occurring in cooler, more northern areas, with smaller birds in warmer, more southern areas. Measurements of 34 adult specimens I examined with no data all fell well within the ranges of measurements for specimens with data. Although sample sizes are small, those specimens from more northern areas in Arkansas, Missouri, and S. Carolina averaged longer wings, and hence probably body size, than those from Florida. See Subspecies and Measurements, below; also see Appendix 1 .

Subspecies

Two subspecies recognized (Peters 1948, American Ornithologists' Union 1957). Although formerly treated as separate species, these appear to be weakly differentiated, allopatric subspecies (Mayr and Short 1970).

C. p. principalis (Linnaeus, Linnaeus 1758a); type locality restricted to S. Carolina. Entire range of species in se. U.S.

C. p. bairdii (Cassin, Cassin 1863); type locality Cuba. Range restricted to island of Cuba. Characters given to diagnose this race by Ridgway (Ridgway 1914b) included smaller size (wing 236-255 mm and culmen 58-61 mm vs. wing 240-263 mm and culmen 61-72.5), white stripe on side of head extending anteriorly nearly to rictus, and nasal tufts smaller. In his original description of C. p. bairdii, Cassin (Cassin 1863) described birds from Cuba as being much like U.S. birds, but smaller, having black feathers at front of crest longer than scarlet feathers just behind them, and in having white line of neck extending almost to bill. In C. p. principalis, scarlet feathers of crest said to be longer than black feathers just in front of them, and the white line extending up each side of neck to end farther back from bill (usually beneath middle of eye). While Cuban Ivory-billed averages smaller than U.S. specimens in bill dimensions, it overlaps Florida specimens greatly in wing, tail, and tarsal measurements (Short 1982) and there is considerable variation among and overlap between Cuban and Florida specimens in plumage characteristics (Cory 1886, Short 1982); see also Appendix 1 .


EBIRD GROUP (MONOTYPIC)

Ivory-billed Woodpecker (Northern) Campephilus principalis principalis Scientific name definitions

Distribution

SE USA (probably extinct).

EBIRD GROUP (MONOTYPIC)

Ivory-billed Woodpecker (Cuban) Campephilus principalis bairdii Scientific name definitions

Distribution

Cuba (probably extinct).

Related Species

Thought closely related, and certainly most similar in appearance, to Imperial Woodpecker; the 2 species sometimes regarded as forming a superspecies (Mayr and Short 1970, Short 1982, Short and Horne 1990). Genus Campephilus currently comprises 11 species (Winkler and Christie 2002).

Fossil History

The “fossil” record for the Ivory-billed Woodpecker includes considerable skeletal material of recent origin found in association with excavation of archaeological sites. Among these are sites in Illinois (Parmalee 1958), Ohio (Wetmore 1943a, Goslin 1945), W. Virginia (Parmalee 1967b), and Georgia (Van Der Schalie and Parmalee 1960). Considering the prominent trade in Ivory-billed Woodpecker bills among Native Americans (e.g., Catesby 1731, Jackson 2004), the presence of Ivory-billed mater-ial associated with archaeological sites outside of se. U.S. and Cuba cannot be taken as indicating a broader range for the species.

How did this species come to be in the se. U.S. and Cuba? Presumably its ancestors arrived from n. South America or Central America, since these are the regions where Campephilus woodpeckers are most abundant. Two routes of arrival within the modern range of Ivory-billeds seem possible: through n. Mexico and around the Gulf Coast to the southeastern states and then to Cuba, or from the Yucatán Peninsula to Cuba, and then to the south-eastern states.

Good evidence supports the notion that ancestral Ivory-billed Woodpeckers may have come through Mexico and across the Gulf Coast region of Texas to the se. U.S. and then from Florida to Cuba. During Pleistocene ice ages, sw. U.S. was much wetter and supported forests where today we find desert. Brodkorb (Brodkorb 1970, Brodkorb 1971) described a fossil Ivory-billed relative, Campephilus dalquesti, from Scurry Co., northwest of Abilene in w. Texas, where it lived during the Upper Pliocene perhaps 4 million yr ago. Lowered sea levels during the peak of Pleistocene glaciation meant that peninsular Florida extended much closer to Cuba, thus facilitating dispersal of Ivory-billed Woodpeckers across the Flor-ida Straits (Jackson 1991c).

Lowered sea levels during Pleistocene glaciation would also have brought the Yucatán Peninsula of Mexico closer to Cuba, facilitating movement of Ivory-billed Woodpeckers from Mexico to Cuba to Florida. This is a puzzle that may never truly be answered, but one worthy of further investigation.

There is a third possibility. Early explorers noted a considerable trade in live birds between peoples of Cuba and peninsular Florida (Jackson 2004). Perhaps Ivory-billeds were introduced to Cuba sometime before the arrival of Columbus in the New World. Native Americans placed great value on these woodpeckers. If any were taken captive and kept alive, their powerful bills would certainly have facilitated escape.

Recommended Citation

Jackson, J. A. (2020). Ivory-billed Woodpecker (Campephilus principalis), version 1.0. In Birds of the World (A. F. Poole and F. B. Gill, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.ivbwoo.01